Phenols and γ ‐Lactams from the Aerial Part of Pseudolysimachion linariifolium subsp. dilatatum

Linariifolioside II ( 1 ) and (2 S )‐2‐hydroxy‐5‐oxoproline methyl ester ( 2 ), two new compounds along with 13 known compounds were obtained from the aerial part of Pseudolysimachion linariifolium Holub subsp. dilatatum ( Nakai & Kitag .) D.Y. Hong . Their chemical structures were revealed mainly through NMR and MS data. The absolute configuration of 2 was deduced by comparing its experimental CD with the calculated ECD spectra. At a concentration of 1 m m , total antioxidant capacities of compounds 1 – 15 were measured using a rapid ABTS method in vitro . Compounds 1 , 3 – 5 , and 11 – 14 exhibited approximately equal antioxidant capacity to that of vitamin C (Vc).